<?php

require_once('include/salmon.php');
require_once('include/crypto.php');
require_once('include/items.php');
require_once('include/follow.php');
require_once('include/Contact.php');

function salmon_return($val) {

	if($val >= 400)
		$err = 'Error';
	if($val >= 200 && $val < 300)
		$err = 'OK';

	logger('mod-salmon returns ' . $val);
	header($_SERVER["SERVER_PROTOCOL"] . ' ' . $val . ' ' . $err);
	killme();

}

function salmon_post(&$a) {

	$xml = file_get_contents('php://input');

	logger('mod-salmon: new salmon ' . $xml, LOGGER_DATA);

	$nick       = ((argc() > 1) ? trim(argv(1)) : '');
//	$mentions   = (($a->argc > 2 && $a->argv[2] === 'mention') ? true : false);

	
	$importer = channelx_by_nick($nick);

	if(! $importer)
		http_status_exit(500);

// @fixme check that this channel has the GNU-Social protocol enabled


	// parse the xml

	$dom = simplexml_load_string($xml,'SimpleXMLElement',0,NAMESPACE_SALMON_ME);

	// figure out where in the DOM tree our data is hiding

	if($dom->provenance->data)
		$base = $dom->provenance;
	elseif($dom->env->data)
		$base = $dom->env;
	elseif($dom->data)
		$base = $dom;

	if(! $base) {
		logger('mod-salmon: unable to locate salmon data in xml ');
		http_status_exit(400);
	}

	logger('data: ' . $xml, LOGGER_DATA);

	// Stash the signature away for now. We have to find their key or it won't be good for anything.


	$signature = base64url_decode($base->sig);

	// unpack the  data

	// strip whitespace so our data element will return to one big base64 blob
	$data = str_replace(array(" ","\t","\r","\n"),array("","","",""),$base->data);


	// stash away some other stuff for later

	$type = $base->data[0]->attributes()->type[0];
	$keyhash = $base->sig[0]->attributes()->keyhash[0];
	$encoding = $base->encoding;
	$alg = $base->alg;

	// Salmon magic signatures have evolved and there is no way of knowing ahead of time which
	// flavour we have. We'll try and verify it regardless.

	$stnet_signed_data = $data;

	$signed_data = $data  . '.' . base64url_encode($type) . '.' . base64url_encode($encoding) . '.' . base64url_encode($alg);

	$compliant_format = str_replace('=','',$signed_data);


	// decode the data
	$data = base64url_decode($data);

	logger('decoded: ' . $data, LOGGER_DATA);

	// GNU-Social doesn't send a legal Atom feed over salmon, only an Atom entry. Unfortunately
	// our parser is a bit strict about compliance so we'll insert just enough of a feed 
	// tag to trick it into believing it's a compliant feed. 

	if(! strstr($data,'<feed')) {
		$data = str_replace('<entry ','<feed xmlns="http://www.w3.org/2005/Atom"><entry ',$data); 
		$data .= '</feed>';
	} 
 
	$datarray = process_salmon_feed($data,$importer);

	$author_link = $datarray['author']['author_link'];

	if(! $author_link) {
		logger('mod-salmon: Could not retrieve author URI.');
		http_status_exit(400);
	}

	$r = q("select xchan_pubkey from xchan where xchan_guid = '%s' limit 1",
		dbesc($author_link)
	);

	if($r) {
		$pubkey = $r[0]['xchan_pubkey'];
	}
	else {

		// Once we have the author URI, go to the web and try to find their public key

		logger('mod-salmon: Fetching key for ' . $author_link);

		$key = get_salmon_key($author_link,$keyhash);

		if(! $key) {
			logger('mod-salmon: Could not retrieve author key.');
			http_status_exit(400);
		}

		$key_info = explode('.',$key);

		$m = base64url_decode($key_info[1]);
		$e = base64url_decode($key_info[2]);

		logger('mod-salmon: key details: ' . print_r($key_info,true), LOGGER_DEBUG);

		$pubkey = metopem($m,$e);
	}

	// We should have everything we need now. Let's see if it verifies.

	$verify = rsa_verify($compliant_format,$signature,$pubkey);

	if(! $verify) {
		logger('mod-salmon: message did not verify using protocol. Trying padding hack.');
		$verify = rsa_verify($signed_data,$signature,$pubkey);
	}

	if(! $verify) {
		logger('mod-salmon: message did not verify using padding. Trying old statusnet hack.');
		$verify = rsa_verify($stnet_signed_data,$signature,$pubkey);
	}

	if(! $verify) {
		logger('mod-salmon: Message did not verify. Discarding.');
		http_status_exit(400);
	}

	logger('mod-salmon: Message verified.');


	/* lookup the author */

	if(! $datarray['author']['author_link'])
		logger('unable to probe - no author identifier');
		http_status_exit(400);
	}

	$r = q("select * from xchan where xchan_guid = '%s' limit 1",
	   	dbesc($datarray['author']['author_link'])
	);
	if(! $r) {
		if(discover_by_webbie($datarray['author']['author_link'])) {
		$r = q("select xchan_hash from xchan where xchan_guid = '%s' limit 1",
			dbesc($datarray['author']['author_link'])
	   	);
		if(! $r) {
			logger('discovery failed');
			http_status_exit(400);
		}
	}

	$xchan = $r[0];


	/*
	 *
	 * If we reached this point, the message is good. Now let's figure out if the author is allowed to send us stuff.
	 *
	 */

	// First check for and process follow activity

	if(activity_match($datarray['verb'],ACTIVITY_FOLLOW) && $datarray['obj_type'] === ACTIVITY_OBJ_PERSON) {

		$r = q("select * from abook where abook_channel = %d and abook_hash = '%s' limit 1",
			intval($importer['channel_id']),
			dbesc($xchan['xchan_hash'])
		);

		if($r) {
			$contact = $r[0];
			$newperms = PERMS_R_STREAM|PERMS_R_PROFILE|PERMS_R_PHOTOS|PERMS_R_ABOOK|PERMS_W_STREAM|PERMS_W_COMMENT|PERMS_W_MAIL|PERMS_W_CHAT|PERMS_R_STORAGE|PERMS_R_PAGES;

			$abook_instance = $contact['abook_instance'];
			if($abook_instance)
				$abook_instance .= ',';
			$abook_instance .= z_root();


			$r = q("update abook set abook_their_perms = %d, abook_instance = '%s' where abook_id = %d and abook_channel = %d",
				intval($newperms),
				dbesc($abook_instance),
				intval($contact['abook_id']),
				intval($importer['channel_id'])
			);
		}
		else {
			$role = get_pconfig($importer['channel_id'],'system','permissions_role');
			if($role) {
				$x = get_role_perms($role);
				if($x['perms_auto'])
					$default_perms = $x['perms_accept'];
			}
			if(! $default_perms)
				$default_perms = intval(get_pconfig($importer['channel_id'],'system','autoperms'));

			$their_perms = PERMS_R_STREAM|PERMS_R_PROFILE|PERMS_R_PHOTOS|PERMS_R_ABOOK|PERMS_W_STREAM|PERMS_W_COMMENT|PERMS_W_MAIL|PERMS_W_CHAT|PERMS_R_STORAGE|PERMS_R_PAGES;


			$closeness = get_pconfig($importer['channel_id'],'system','new_abook_closeness');
			if($closeness === false)
				$closeness = 80;
		

			$r = q("insert into abook ( abook_account, abook_channel, abook_xchan, abook_my_perms, abook_their_perms, abook_closeness, abook_created, abook_updated, abook_connected, abook_dob, abook_pending, abook_instance ) values ( %d, %d, '%s', %d, %d, %d, '%s', '%s', '%s', '%s', %d, '%s' )",
				intval($importer['channel_account_id']),
				intval($importer['channel_id']),
				dbesc($contact['xchan_hash']),
				intval($default_perms),
				intval($their_perms),
				intval($closeness),
				dbesc(datetime_convert()),
				dbesc(datetime_convert()),
				dbesc(datetime_convert()),
				dbesc(NULL_DATE),
				intval(($default_perms) ? 0 : 1),
				dbesc(z_root())
			);
			if($r) {
				logger("New GNU-Social follower received for {$importer['channel_name']}");

				$new_connection = q("select * from abook left join xchan on abook_xchan = xchan_hash left join hubloc on hubloc_hash = xchan_hash where abook_channel = %d and abook_xchan = '%s' order by abook_created desc limit 1",
					intval($importer['channel_id']),
					dbesc($xchan['xchan_hash'])
				);
		
				if($new_connection) {
					require_once('include/enotify.php');
					notification(array(
						'type'       => NOTIFY_INTRO,
						'from_xchan'   => $xchan['xchan_hash'],
						'to_xchan'     => $importer['channel_hash'],
						'link'         => z_root() . '/connedit/' . $new_connection[0]['abook_id'],
					));

				if($default_perms) {
// @fixme!!!
					// Send back a sharing notification to them
					$x = gnusoc_follow($importer,$new_connection[0]);
					if($x)
						proc_run('php','include/deliver.php',$x);

				}

				$clone = array();
				foreach($new_connection[0] as $k => $v) {
					if(strpos($k,'abook_') === 0) {
						$clone[$k] = $v;
					}
				}
				unset($clone['abook_id']);
				unset($clone['abook_account']);
				unset($clone['abook_channel']);

				$abconfig = load_abconfig($importer['channel_hash'],$clone['abook_xchan']);

		 		if($abconfig)
					$clone['abconfig'] = $abconfig;

				build_sync_packet($importer['channel_id'], array('abook' => array($clone)));

			}

			http_status_exit(200);
		}
	}

	}
	// 
	// ... fixme


	// Otherwise check general permissions

	if(! perm_is_allowed($importer['channel_id'],$xchan['xchan_hash'],'send_stream')) { 

		// check for and process ostatus autofriend


		// ... fixme


		// otherwise 

		logger('mod-salmon: Ignoring this author.');
		http_status_exit(202);
		// NOTREACHED
	}

	unset($datarray['author']);

	$parent_item = null;
	if($datarray['parent_mid']) {
		$r = q("select * from item where mid = '%s' and uid = %d limit 1",
			dbesc($datarray['parent_mid']),
			intval($importer['channel_id'])
		);
		if(! $r) {
			logger('mod-salmon: parent item not found.');
			http_status_exit(202);
		}
		$parent_item = $r[0];
	}
	

	if(! $datarray['author_xchan'])
		$datarray['author_xchan'] = $xchan['xchan_hash'];

	$datarray['owner_xchan'] = (($parent_item) ? $parent_item['owner_xchan'] : $xchan['xchan_hash']);


	$r = q("SELECT edited FROM item WHERE mid = '%s' AND uid = %d LIMIT 1",
		dbesc($datarray['mid']),
		intval($importer['channel_id'])
	);


	// Update content if 'updated' changes
	// currently a no-op @fixme

	if($r) {
	   if((x($datarray,'edited') !== false) && (datetime_convert('UTC','UTC',$datarray['edited']) !== $r[0]['edited'])) {
		   // do not accept (ignore) an earlier edit than one we currently have.
		   if(datetime_convert('UTC','UTC',$datarray['edited']) > $r[0]['edited'])
			   update_feed_item($importer['channel_id'],$datarray);
	   }
	   http_status_exit(200);
	}

	if(! $datarray['parent_mid'])
		$datarray['parent_mid'] = $datarray['mid'];
		
	$datarray['aid'] = $importer['channel_account_id'];
	$datarray['uid'] = $importer['channel_id'];

	logger('consume_feed: ' . print_r($datarray,true),LOGGER_DATA);

	$xx = item_store($datarray);
	$r = $xx['item_id'];

// if this is a reply, do a relay?

	http_status_exit(200);
}


function gnusoc_follow($importer,$xchan) {


}